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Detection rules › Kusto

AppServices AV Scan with Infected Files

Severity
informational
Time window
1d
Author
SecurityJedi
Source
github.com/Azure/Azure-Sentinel

'Identifies if an AV scan finds infected files in Azure App Services.'

Rule body kusto

id: 9d0295ee-cb75-4f2c-9952-e5acfbb67036
name: AppServices AV Scan with Infected Files
description: |
  'Identifies if an AV scan finds infected files in Azure App Services.'
severity: Informational
requiredDataConnectors: []
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 1
query: |
  let timeframe = ago(1d);
  AppServiceAntivirusScanAuditLogs
  | where NumberOfInfectedFiles > 0
  | extend timestamp = TimeGenerated
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: AzureID
        columnName: _ResourceId
version: 1.0.3
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: SecurityJedi
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Platform" ]

Stages and Predicates

Parameters

let timeframe = ago(1d);

Stage 1: source

AppServiceAntivirusScanAuditLogs

Stage 2: where

| where NumberOfInfectedFiles > 0

Stage 3: extend

| extend timestamp = TimeGenerated

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
NumberOfInfectedFilesgt
  • 0 transforms: cased

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

FieldSource
timestampextend